"But fate is a fickle friend. While James was away, I experienced an emotional and physical release of an unholy trinity of trauma I’d experienced 19 years earlier—a rape, pregnancy, and abortion."
It's called competition anxiety. You simply didn't make your relationship with your ex a priority. Your fears always came first. I'd bet they still do.
At least you released the poor simp!
You shouldn't be married - to anybody. You should seek CBT...